Demystifying the Operational Transconductance Amplifier

Operational transconductance amplifiers (OTAs) are often among the least understood analog components. However, these devices serve a very useful function that is being implemented on a regular basis in many integrated circuits as an element for more advanced purposes; the current feedback amplifier is among the most prominent example. The purpose of this application report is to show how this building block operates. It also develops several examples of how this type of component can be put to good use for many applications.